Our invention relates to a sprocket assembly for use as either a drive or idler wheel for the tracks or endless chain belts of a track type vehicle. Our invention is directed more specifically to such a sprocket assembly capable of damping the forces exerted thereon in all of the axial, radial, and rotational directions of the sprocket assembly.
Sprocket assemblies of the type under consideration usually comprise an inner rim mounted in a fixed relation to the hub, and an outer rim disposed concentrically outwardly of the inner rim and having a series of sprocket teeth for engagement with the track assembly of the vehicle. A variety of devices have been suggested and used to provide more or less elastic connections between the inner and outer rims of the sprocket assemblies. One known arrangement includes torque pins mounted between the inner and outer rims via elastic members, such that the elastic members bear radial loads. However, the inner and outer rims make metal to metal contact via the torque pins when loaded in both axial and rotational directions of the sprocket assembly. Consequently the torque pins and other parts making direct contact therewith have been susceptible to rapid wear.
Another conventional device has rubber pads interposed between radial teeth on the inner and outer rims for elastically bearing loads in both radial and rotational directions. Here again, however, metal to metal contact has been resorted to for bearing the relative axial thrust of the inner and outer rims. As an additional drawback the rubber pads are of such construction that they cannot possibly be preloaded prior to the assemblage of the sprocket assembly. They have had to be preloaded in place between the inner and outer rims, which fact has made the assemblage of the sprocket assembly very difficult. The pads have also been liable to be preloaded to different degrees depending upon the dimensional accuracies of the related parts.